Hah, I slashed a corner with mine and went ahead lightly sanded the case and used a canister of matte black paint for the first coat, then wet sanded the next day. After a day of drying, I went ahead and started on the second serving of matte black.
Heres my Antec 300
Core i7 920
Intel DX58SO mobo
Noctua NH-U12 1366 Cooler
EVGA GTX 275 FTW Edition
OCZ Stealth 700w PSU
I wanted to paint the inside of my case black so here is the before pics.
Here it is afterwards